Apple is readying its forces for a massive push into what has the potential to be its largest market, China.

This Friday, just in time for Chinese New Year which falls on January 23, the iPhone 4S will go on sale for the first time in China, via China Unicom.

The bigger news, though, is that authorities have approved an Apple-made mobile phone that can run on the network of China Telecom, the country’s third-largest wireless carrier. It is not clear whether the device is an iPhone 4S, iPhone 4 or iPhone 3G.

According to a report in the Wall Street Journal, Apple still has a few more hurdles to jump before it can bring the device to China Telecom, but this first step shows it’s a process Apple is undertaking in earnest.

From here, there’s a chance Apple will also get on board with China’s largest mobile operator, China Mobile, a deal that’s been talked about for a while but has never solidified.

Each network has millions of subscribers, with operators sure to offer heavy discounts to secure the potential network traffic.

The iPhone 4S will be launched in an additional 21 countries on Friday, including Bolivia, Ecuador and Jamaica.